The present invention relates to a device for holding a plurality of blades such as might be used for crimping a moving multipart paper web at a plurality of locations along its length. Such a holder is particularly useful in machines for collating several paper webs, such as might be done in the manufacture of business forms.
Multipart, preprinted business forms are commonly used, for instance, where it is desired to make multiple copies of a document at the same time. In manufacturing such forms, a single web is printed for each part, or layer, of the form, and the individual webs are then supplied to a collator for proper arrangement into layers. Depending upon the particular forms, carbon paper may be interleaved between the various printed parts of the multipart web. In the production of continuous forms, after collating, a perforation is provided across the web at a plurality of predetermined locations, so that individual forms may be separated from the web for use. The individual forms typically are not separated until immediately before or after use, and the forms are packaged for shipment and/or storage by folding the web in accordion-like fashion along the perforations.
In order to keep the various parts of the form together until such time as it is desired to separate them, it is common to provide a plurality of crimps along each edge of the multipart web during collating. The crimping is normally performed by a series of crimp blades, each of which has a plurality of teeth for cooperating with grooves provided in an anvil surface. The teeth puncture and pass through the web into the grooves of the anvil surface, thereby providing a plurality of slots through the parts of the web. The crimp blades are designed, however, to cut the paper on only three sides of each slot. The small portions of paper orginally located where the slots are formed are thus not severed from the web, but remain attached and are pushed downwardly through the slot formed in the underlying parts. These small paper tabs interlock with one another to hold the various parts together.
The crimp blades are usually mounted to one or more blade holders, an example of which is disclosed in U.S. Pat. No. 2,935,002, issued May 3, 1960 to Robinson, which in turn are mounted to a rotatable shaft. The multipart web is passed between the blade holders and the cooperating anvil surface, and the blade holder shaft is rotated at a speed such that the teeth of the crimp blades and the web approach each other at the same linear speed. Thus, as the web is passed by the blade holders, the blades crimp the web in a pattern predetermined by the arrangement of the blades along the holders.
In addition to the perforations provided across the multipart web, and the crimping provided along the edges of the web, the web is further provided with a series of holes along each of its edges. These holes may be used for advancing the web, both during manufacture of the forms, and during their subsequent use, for instance, where the individual forms are prepared by a computer printer. Typically, the holes are disposed along the edge of the web at a spacing of 0.50 inch (1.27 cm) center-to-center, and equipment used with forms has been designed to be compatible with such spacing.
Thus, to be effective, the crimps must be located along the web so as to avoid the holes. Accordingly, as can be seen in FIG. 1, the crimps are typically centered 0.25 inch (0.635 cm) from the centers of adjacent holes, and are thereby separated from other crimps by an integer number of half-inches.
The perforations separating successive forms represent yet another constraint on the location of the crimps. These cross perforations, typically formed on the web after crimping, must be located so as not to fall on the holes. Thus, as seen in FIG. 1, the perforations are also located 0.25 inch (0.635 cm) from the centers of adjacent holes. It is not desirable, however, for the crimps to fall where a cross perforation will occur. In such a case, the crimps could cause premature, partial separation of individual forms along the perforation, thereby making accidental full separation much more likely. Moreover, the crimps prevent even, neat folding along the perforations, interfering with the proper arrangement of the web for storage and/or shipping.
The separation between consecutive perforations along the web is, of course, determined by the desired length for the form. In the United States, the two most common lengths for forms are 81/2 inches (21.6 cm) and 11 inches (27.9 cm), and in Europe, the most common lengths are 8 inches (20.3 cm) and 12 inches (30.5 cm). In the case of 8-inch, 11-inch and 12-inch forms, as well as any other form of a length of an integer number of inches, it can be seen that consecutive perforations are separated by an even number of half-inch intervals. The crimp blades can therefore be arranged to provide crimps in intervals of an even number of half-inches. By separating the initial crimp from the initial perforation by an odd number of half-inch intervals, the perforations and crimps will not coincide.
This approach is not usable in the case of 81/2 inch forms. With 81/2 inch forms (21.6 cm), the first and second cross perforations are separated by an odd number of half-inch intervals (17), but the first and third perforations are separated by an even number of such intervals (34). Therefore, with crimp blade spacing in an even number of half-inch intervals, it is not possible to prevent at least some crimps from coinciding with cross-perforations. Thus, it can be seen that a particular arrangement of crimp blades that is suitable for use with 11-inch forms is not usable with 81/2 inch forms, and vice versa.
Typically, the problem of crimp spacing for different sizes of forms is solved by providing two different crimp blade holders, one size for each of the different forms. When the collator is to be readied for changing from one size form to another, the blade holders mounted to the rotatable shaft must be disassembled and removed from the shaft, and a new set of blade holders providing a different spacing must be installed. This represents a relatively time-consuming process, and requires the operator of the collator to keep two sets of crimp blade holders on hand. Moreover, two sets of parts is costly. In addition, it is necessary to change the gearing for driving the crimp blade holder shaft in synchronism with the web, which is also time-consuming and inconvenient.
A second method is to rotate the crimp blade holder at different speeds, depending upon the size of the form. This method also requires a gearing change, and requires that with at least some sizes of forms, the blade holder must be rotated at a different speed than that of the web. The different speeds may result in tearing of the web by the crimp blades.
What is needed, therefore, is a single set of crimp blade holders that are capable of use with either 81/2 or 11 inch forms. Such holders should be capable of arranging crimp blades such that in either case, crimps do not coincide with perforations along the multilayer web. Further, use of the crimp blade holders with one size of form following use with another size form should not require any modifications or adjustments to the blade holders, or changing of driving gears to synchronize crimping to form length.